Motor vehicle crashes are the leading cause of death among children in the United States. Child safety seats provide protection and have been observed to reduce death and injury rates by more than 70% when properly used. Studies have observed that only 10% to 20% of children are correctly harnessed into correctly installed seats. One of the most common errors involves the installation of the child safety seat in the vehicle. Child safety seats are installed using the vehicle seat belt or an independent Lower Anchors and Tethers for Children (LATCH) strap sold with the seat. The LATCH system is designed to make installation of child safety seats easier by providing a strap with the seat and two lower anchors in the vehicle onto which a child seat is attached. The vehicle seat belt or flexible LATCH seat anchor strap must be aggressively tensioned to achieve proper installation. The most common error associated with LATCH installations has been observed to be a loose lower anchor strap, which was observed in 30% of installations. Loose anchor straps increase the relative movement between the child safety seat and the vehicle in a crash thereby reducing the effectiveness of the seat at controlling the child's deceleration and increasing the impact of the child, in particular of the head, with the vehicle interior, seat, or harness. This project will develop an inexpensive device to ensure that child safety seat anchor straps are properly installed. PUBLIC HEALTH RELEVANCE: The societal benefit of the proposed device is that, if successful, it will inexpensively and easily improve the safety of all LATCH system child safety seats by reducing the prevalence of anchor strap under tensioning. The population of interest for this device is virtually all child safety seat installers/users, which includes parents, grandparents, and child care providers. The available market for the proposed device exceeds 5 million units annually in the U.S. alone. There are approximately 30 million children 6 years old and younger in the U.S. By law, children in this age group must be restrained in a child safety seat. The proposed device provides benefit in nearly all of these seat installations.